A presentation by Ann-Kathrin Rink

introduction facts about pluto a dwarf among giants the discovery sources

The solar system 8 planets (pluto is not a planet anymore) Kuiper belt objects (KBOs)

Region of the solar system beyond neptunes orbit is a bit like the asteroid belt (but much larger) 30 AU to 55 AU away from the sun The Kuiper Belt KBOs first KBO was discovered in 1992 home of at least 2 dwarf planets Eris & Pluto

3 moons Diameter 2320 km Mass: 0,0021 Earthmass Average distance from sun: 6 billion km Maximum: 7,4 billion km Minimum: 4,4 billion km Eccentricity of its orbit 0,25 Compared with other planets, the eccentricity is extremely high e.g. Earth : 0,017 ; Neptune: 0,009 Orbital period: 248,6 earth years Rotation period: 6,4 earth days

Was stripped of his fully planet status August 2006 reclassified as a dwarf planet Why? discovery of a number of KBOs of similar if not greater size if the IAU did not action like that, other KBOs would have become planets some astronomers question plutos status because of its size more similarities with the KBOs

1905 Percival Lowell hypothesized the possibility of a planet X Based on perturbations of Neptune and Uranus influence of other bodys gravity Calculated the approximate position was not able to find it before he died in 1916

1919 W. H. Pickering recalculated the position of the planet X failed to find Pluto, too

… C. W. Tombaugh finally discovered Pluto on the 18th February in 1930 Used calculation of is predecessors Fotographes certain sections twice interval of 6 days Searching for a wandering star

Analysed these pictures with a blink comparator shows both pictures in series a wandering star will blink Today we know that Pluto s mass is not big enough to perturb Uranus and Neptunes orbit... In the end Plutos discovery must have been a lucky break

Thank you for your attention Sources: Harenbergs Schlüsseldaten Astronomie